mac80211: add debug knobs for fair queuing

This adds a debugfs entry to read and modify some fq parameters.

This makes it easy to debug, test and experiment.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
[remove module parameter for now]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index b251b2f7f8dd8c6859ec5d32530e741530835f40..2906c1004e1a471602dfdfa6a7420e57a68c5b77 100644 (file)
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -10,6 +10,7 @@
 
 #include <linux/debugfs.h>
 #include <linux/rtnetlink.h>
+#include <linux/vmalloc.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 #include "rate.h"
@@ -70,6 +71,177 @@ DEBUGFS_READONLY_FILE(wep_iv, "%#08x",
 DEBUGFS_READONLY_FILE(rate_ctrl_alg, "%s",
        local->rate_ctrl ? local->rate_ctrl->ops->name : "hw/driver");
 
+struct aqm_info {
+       struct ieee80211_local *local;
+       size_t size;
+       size_t len;
+       unsigned char buf[0];
+};
+
+#define AQM_HDR_LEN 200
+#define AQM_HW_ENTRY_LEN 40
+#define AQM_TXQ_ENTRY_LEN 110
+
+static int aqm_open(struct inode *inode, struct file *file)
+{
+       struct ieee80211_local *local = inode->i_private;
+       struct ieee80211_sub_if_data *sdata;
+       struct sta_info *sta;
+       struct txq_info *txqi;
+       struct fq *fq = &local->fq;
+       struct aqm_info *info = NULL;
+       int len = 0;
+       int i;
+
+       if (!local->ops->wake_tx_queue)
+               return -EOPNOTSUPP;
+
+       len += AQM_HDR_LEN;
+       len += 6 * AQM_HW_ENTRY_LEN;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(sdata, &local->interfaces, list)
+               len += AQM_TXQ_ENTRY_LEN;
+       list_for_each_entry_rcu(sta, &local->sta_list, list)
+               len += AQM_TXQ_ENTRY_LEN * ARRAY_SIZE(sta->sta.txq);
+       rcu_read_unlock();
+
+       info = vmalloc(len);
+       if (!info)
+               return -ENOMEM;
+
+       spin_lock_bh(&local->fq.lock);
+       rcu_read_lock();
+
+       file->private_data = info;
+       info->local = local;
+       info->size = len;
+       len = 0;
+
+       len += scnprintf(info->buf + len, info->size - len,
+                        "* hw\n"
+                        "access name value\n"
+                        "R fq_flows_cnt %u\n"
+                        "R fq_backlog %u\n"
+                        "R fq_overlimit %u\n"
+                        "R fq_collisions %u\n"
+                        "RW fq_limit %u\n"
+                        "RW fq_quantum %u\n",
+                        fq->flows_cnt,
+                        fq->backlog,
+                        fq->overlimit,
+                        fq->collisions,
+                        fq->limit,
+                        fq->quantum);
+
+       len += scnprintf(info->buf + len,
+                        info->size - len,
+                        "* vif\n"
+                        "ifname addr ac backlog-bytes backlog-packets flows overlimit collisions tx-bytes tx-packets\n");
+
+       list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+               txqi = to_txq_info(sdata->vif.txq);
+               len += scnprintf(info->buf + len, info->size - len,
+                                "%s %pM %u %u %u %u %u %u %u %u\n",
+                                sdata->name,
+                                sdata->vif.addr,
+                                txqi->txq.ac,
+                                txqi->tin.backlog_bytes,
+                                txqi->tin.backlog_packets,
+                                txqi->tin.flows,
+                                txqi->tin.overlimit,
+                                txqi->tin.collisions,
+                                txqi->tin.tx_bytes,
+                                txqi->tin.tx_packets);
+       }
+
+       len += scnprintf(info->buf + len,
+                        info->size - len,
+                        "* sta\n"
+                        "ifname addr tid ac backlog-bytes backlog-packets flows overlimit collisions tx-bytes tx-packets\n");
+
+       list_for_each_entry_rcu(sta, &local->sta_list, list) {
+               sdata = sta->sdata;
+               for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
+                       txqi = to_txq_info(sta->sta.txq[i]);
+                       len += scnprintf(info->buf + len, info->size - len,
+                                        "%s %pM %d %d %u %u %u %u %u %u %u\n",
+                                        sdata->name,
+                                        sta->sta.addr,
+                                        txqi->txq.tid,
+                                        txqi->txq.ac,
+                                        txqi->tin.backlog_bytes,
+                                        txqi->tin.backlog_packets,
+                                        txqi->tin.flows,
+                                        txqi->tin.overlimit,
+                                        txqi->tin.collisions,
+                                        txqi->tin.tx_bytes,
+                                        txqi->tin.tx_packets);
+               }
+       }
+
+       info->len = len;
+
+       rcu_read_unlock();
+       spin_unlock_bh(&local->fq.lock);
+
+       return 0;
+}
+
+static int aqm_release(struct inode *inode, struct file *file)
+{
+       vfree(file->private_data);
+       return 0;
+}
+
+static ssize_t aqm_read(struct file *file,
+                       char __user *user_buf,
+                       size_t count,
+                       loff_t *ppos)
+{
+       struct aqm_info *info = file->private_data;
+
+       return simple_read_from_buffer(user_buf, count, ppos,
+                                      info->buf, info->len);
+}
+
+static ssize_t aqm_write(struct file *file,
+                        const char __user *user_buf,
+                        size_t count,
+                        loff_t *ppos)
+{
+       struct aqm_info *info = file->private_data;
+       struct ieee80211_local *local = info->local;
+       char buf[100];
+       size_t len;
+
+       if (count > sizeof(buf))
+               return -EINVAL;
+
+       if (copy_from_user(buf, user_buf, count))
+               return -EFAULT;
+
+       buf[sizeof(buf) - 1] = '\0';
+       len = strlen(buf);
+       if (len > 0 && buf[len-1] == '\n')
+               buf[len-1] = 0;
+
+       if (sscanf(buf, "fq_limit %u", &local->fq.limit) == 1)
+               return count;
+       else if (sscanf(buf, "fq_quantum %u", &local->fq.quantum) == 1)
+               return count;
+
+       return -EINVAL;
+}
+
+static const struct file_operations aqm_ops = {
+       .write = aqm_write,
+       .read = aqm_read,
+       .open = aqm_open,
+       .release = aqm_release,
+       .llseek = default_llseek,
+};
+
 #ifdef CONFIG_PM
 static ssize_t reset_write(struct file *file, const char __user *user_buf,
                           size_t count, loff_t *ppos)
@@ -256,6 +428,7 @@ void debugfs_hw_add(struct ieee80211_local *local)
        DEBUGFS_ADD(hwflags);
        DEBUGFS_ADD(user_power);
        DEBUGFS_ADD(power);
+       DEBUGFS_ADD_MODE(aqm, 0600);
 
        statsd = debugfs_create_dir("statistics", phyd);